Remark 10 
If the polynomial (REF ) has only real roots, then \(\mathbb {N}_p\)  is an ECT-space on the whole real line, and in particular on any bounded interval \([a,b]\) . On the other hand, if the characteristic polynomial has also complex roots, then \(\mathbb {N}_p\)  is an ECT-space on sufficiently small intervals; see [1]}. More precisely, \(\mathbb {N}_p\)  is an ECT-space on any interval \([a,b]\)  such that
\( b-a<\mathfrak {l}_p. \) 
